There are databases that manage an index of table records so as to be able to rapidly search for a table record stored in the database. In a database system that manages such a database, when a database table is updated, the index is also updated at the same time.
When a write error occurs while updating the index in the database system, there is the danger that the index data could be corrupted, making it impossible to execute a table record search using the index. It is supposed here that a state in which the index data has been corrupted is a “logic crash”.
A technique for restoring a database in this state without stopping the provision of database services is known (for example, refer to PTL 1).